Platelet Activating Factor (PAF), 1-0-hexadecyl/octadecyl-2-acetyl-sn-glyceryl-3-phosphorylcholine, is an ether lipid produced by a variety of different cell types. Recent studies [Snyder, F., Ann. Rep. Med. Chem., 17, 243 (1982); Pinckard, R. N., et. al., J. Adv. Inflammation Res., 4, 147 (1982); O'Flaherty, J. T., et. al., Clin. Rev. Allergy, 1, 353 (1983); Vargaftig, B. B., et. al., J. Trends. Pharmacol. Sci., 4, 341 (1983)] have shown PAF to be an important mediator of allergic disease. Included among the physiological processes in which PAF is implicated are aggregation of platelets, inflammation, smooth muscle contraction, pain and edema. PAF is implicated in asthma, respiratory distress syndrome, lung edema and other inflammatory and cardiovascular diseases.
The compounds of the present invention have proven to be specific inhibitors of the biological effects of PAF and are consequently useful for the treatment of asthma, anaphylactic and septic shock, psoriasis, bowel necrosis, adult respiratory distress syndrome, transplant rejection, thrombosis, stroke, cardiac anaphylaxis and cancer.